"Early on August 28, 2012, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi-NPP satellite captured this nighttime view of Tropical Storm Isaac and the cities near the Gulf Coast of the United States. The image was acquired just after local midnight by the VIIRS "day-night band," which detects light in a range of wavelengths from green to near-infrared and uses light intensification to enable the detection of dim signals. In this case, the clouds of Isaac were lit by moonlight."